Seoul (CNN) -- Thousands of protesters clashed with the police Sunday in the South Korean coastal city of Busan in a demonstration against layoffs at one of the country's shipbuilding companies.

Police estimated that more than 7,000 protesters rallied against layoffs at Hanjin Heavy Industries and for the rights of temporary workers.

Police fired water cannons with diluted tear gas solution on the crowds after warning the crowds to disperse on the streets. Organizers said the demonstrators included children and elderly people.

"They created this conflict and have made what was a peaceful movement into a mess," according to Song Kyeong-dong, one of the organizers of the protest, who said they had requested permission to hold a peaceful march but were blocked by the police.

Protesters called the police tactic inhumane, saying the tear gas-water mixture was dangerous and painful.

But police disagreed with the characterization.

"There is a standard dilution ratio in the manual," the Busan Police Agency said. "We diluted it further down."

The workers' right movement mushroomed after Hanjin announced in January it would layoff 290 workers.

The protest has gone largely unnoticed by the local media, and protestors have been using Twitter and social media to rally support.

Organizers of the protest said they are putting plans together for another march and will carry it out within a month.